Dental cavity-impression tray.



No. 883,592. PATENTED MAR. 31, 1908.

' T. G. TRIGGER.

DENTAL CAVITY IMPRBSSIO-N TRAY.

APPLICATION rI Lnn APR.18,190'7.

El nue ntoz 04 THE NORRIS P215125 co.. WASHINJTOP, n

THEODORE O. TRIGGER, OF ST. THOMAS, ONTARIO, CANADA.

' DENTAL cAvIrY-nvrPnnssIoN TRAY.

Specification of Letters Patent.

Patented March 31, 1908.

Application filed April 18, 1907. Serial No. 369,026.

To all whom it may concern:

Be it known that I, THEODORE CLARK TRIGGER, a subject of the King of Great Britain, residing-at St. Thomas, in the Province of Ontario, Dominion of Canada, have invented certain new and useful Improvements in Cavity-Impression Trays, of which the following is a s ecifioation.

My invention re ates to cavity impression trays for use in dental work, and has for its object to provide a simple and cheaply constructed instrument for receiving and holding wax and im ressing the same upon a tooth, together with means whereby the Wax may be locked u on said plate when it is impressed in order t at it may be removed upon the instrument from the cavity.

My invention resides specifically in the features of construction and arrangement to be hereinafter described and pointed out in the accompanying drawings, in which,

Figure 1 is an elevation of my device partly broken away to show the connection between the handle and the shank of the instrument, and Figs. 2, 3, 4 and 5 are elevations of my device illustrating slight changes in shape.

According to my invention I provide a series of instruments each of which are slightly changed in shape'and contour in order that the difierences in size, shape and position of the teeth may be provided for, and which together form a complete set.

In the practical embodiment of my invention I provide an instrument comprising a shank 1, having a reduced threaded extension 2 by which the same may be attached to a suitable handle 3. Mounted upon the outer end of the shank and preferably cast integral therewith is the impression tray comprising an undercut wax-holding face 4, and a continuous ledge 5. By this means when the wax is placed upon the face 4 and is pressed tightly against the tooth, the wax spreads beneath the undercut ledge 5, and is t ereby held from displacement when removed from the tooth. To further provide against any chance of the wax slipping, I provide openings 6 through the thickness of the tray, into which holes the wax is also adapted toflow when being impressed.

Having thus fully described my invention, I claim:

In an instrument of the class described, the combination of a shank provided with a reduced threaded end, adapted for attachment to a suitable handle, and a wax-holding tray integrally mounted upon the other end of said shank, and provided with a continuous undercut ledge extending therearound, and openings arranged therethrough for the purpose specified. V

In testimony whereof I affix my signature in presence of two Witnesses.

THEODORE C. TRIGGER. Witnesses:

EDGAR C. SANDERS, AGNES ETHEL MOORE. 

